The desire to reduce automotive fuel consumption and emissions is well documented. Therefore, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle currently being developed for this purpose. In general, electrified vehicles differ from conventional motor vehicles because they are selectively driven by one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on the internal combustion engine to drive the vehicle.
A high voltage battery pack typically powers the electric machines and other electrical loads of the electrified vehicle. The battery pack typically includes a plurality of battery cells that are compressed together to a specific extent in one or more cells stacks or modules. The battery cells may expand or swell due to internal pressure build-up caused by electrolyte decomposition. Over time, this can result in battery cell degradation and associated loss of performance.